Hi Thomas,Thank you for the informative comparison article about Nikon's 35mm lens family and sorry for digging this topic at this time.Could you please spare your time and add the new Nikon 35mm f/1.8G ED into this comparison row? I really love the quality control, durability and light weight of the new lens, but not sure if it's as good as the elder brothers. Thank for your help.

Hello tnonline, and welcome to the friendly Camera Labs forum!To enjoy your stay here please have a look at the house-rules!----As you've probably seen, I've just recently tested the new 35/1.8G from Nikon. The review-in-progress will soon be replaced by my full review. I've also been working on updating my Nikon 35/1.4G review to my standard tests on a D800. So the material for an updated comparison (including the Sigma 35/1.4 DG HSM) is already there. Just give me some time to write it up.

As to your question: No, the metering system adapts the automatic exposure to any fluctuations in transmission of any lens. This is the same when you put a dark filter in front of the lens: the automatic will compensate for this.

Only if you manually expose this lens and compare it to e.g. the 35/2.0D or 35/1.4G at trhe same exposure you can see that less light is transmitted to the sensor.

I was comparing my kit lens (Nikkor 18-105mm) against the Nikkor 35mm 1.8 lens because I was leaning towards the 35mm lens looked much softer than the kit lens. On a tripod though it looks pretty much the same. Must have been the Kit lens VR. What I found through was the same light issue.

After comparing them in Lightroom, I seen I have to boost the EV on the 35mm. So your comment about the cameras metering system adapting doesnt seem to make sense to me.

I had both lenses attached to a D90, on a tri pod, same lighting, set at the same F-Stop and focal length. If the camera were to adapt, wouldn't the post pics be the same exposure?

I was leaning towards the same question, "DO I need to set my camera for +.7EV when using this lens?"It almost seems like I would need to in this case...right? Am I missing something?

Hello changedsoul, and welcome to the friendly Camera Labs forum!To enjoy your stay here please have a look at the house-rules!----There are some fluctuations in exposure that depend on the proper closing of the aperture through the mechanical aperture lever.I found that some lenses/copies show some differences here. So if the camera body moves the aperture-elver to the say f5.6 position, the lens might close to something between f4.8 and f6.8. And because exposure is calculated before the aperture closes the camera cannot compensate for this. It can only compensate for any differences in transmission that occur in the wide-open state before the shot is taken.So put any polarizer of ND filter on the lens and the camera will compensate for it. If the lens has a mis-aligned aperture-lever, the camera cannot compensate.Hope that makes sens.---Btw.: The Olympus OM film-camera was the only SLR-camera that measured exposure during the shot. So there was no such problem. Even shining a flashlight in the camera during a long exposure would immediately (and correctly) close the shutter. try this with any of the modern cameras: They are blind to anything that happens during exposure.

I urge you to read more on optics. At the same focal ratio(f number), the optical system with the largest front element will have the brighter image. Large front element means more photons collected. This is common knowledge to amateur astronomers.

As you know, I'm sure, at the same f-number illumination intensity per unit area is identical. Increasing the entrance pupil size and maintaining the f-number means more photons over a bigger image. But it gets more interesting when the size of the photo-sites gets dragged into the discussion.

Agree with Bob and I think one might need to be careful with retrofocus designs too.

I'm no sage on optics, but I have a number of lenses with the same light drawing power and different front element sizes. On my old Leicas, you just about can't see the front element on some WA lenses as it's so small!